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How to make the ADuC847 enter in the serial download mode progamatically?

Category: Software
Product Number: ADuC847

Hi there, i'm trying to make an application where i can update my board directly from and HMI. Until this day i'm able to do so, but i need to press a reset button and another button regarding the PSEN, as it's the default method to make the processor start in the serial download mode. 

My question is: is there anything i can do to make the processor get into the serial download mode only via software? 

For example: if i put a jmp assembly instruction?